In earlier, animacy-based two-gender Proto-Indo-European, *so was the animate demonstrative. Once the gender system was established, *seh₂ was created using the feminine suffix *-h₂ ; *tod was the inanimate demonstrative in two-gender Proto-Indo-European and was later used as a neuter demonstrative.
*só ~ *tó- [ 1] [ 2]
this
that
Thematic pronominal
masculine
feminine
nominative
*só
*séh₂
genitive
*tósyo
*tósyeh₂s
masculine
singular
dual
plural
nominative
*só
*tóh₁
*tóy
accusative
*tóm
*tóh₁
*tóms
genitive
*tósyo
*?
*tóysoHom
ablative
*tósmead
*?
*tóymos , *tóybʰos
dative
*tósmey
*?
*tóymos , *tóybʰos
locative
*tósmi
*?
*tóysu
instrumental
*tónoh₁
*?
*tṓys
feminine
singular
dual
plural
nominative
*séh₂
*?
*téh₂es
accusative
*tā́m
*?
*téh₂m̥s
genitive
*tósyeh₂s
*?
*téh₂soHom
ablative
*tósyeh₂s
*?
*téh₂mos , *téh₂bʰos
dative
*tósyeh₂ey
*?
*téh₂mos , *téh₂bʰos
locative
*tósyeh₂
*?
*téh₂su
instrumental
*téh₂(e)h₁
*?
*téh₂mis , *téh₂bʰis
neuter
singular
dual
plural
nominative
*tód
*tóy
*téh₂
accusative
*tód
*tóy
*téh₂
genitive
*tósyo
*?
*tóysoHom
ablative
*tósmead
*?
*tóymos , *tóybʰos
dative
*tósmey
*?
*tóymos , *tóybʰos
locative
*tósmi
*?
*tóysu
instrumental
*tónoh₁
*?
*tṓys
*tó-r ( “ there ” )
Proto-Germanic: *þar (see there for further descendants )
*tor gʰi
*tó-ti ( “ so many ” ) (see there for further descendants )
*teh₂-li-, *to-li ( “ so great, to such an extent ” )
Proto-Balto-Slavic:
> ? Proto-Celtic: *talī- ( “ to cost, pay ” ) [ 3]
Proto-Italic: *tālis
Latin: tālis (see there for further descendants )
⇒ *teh₂-li-ko- ; *to-li-ko-
Proto-Balto-Slavic:
Proto-Slavic: *toliko (see there for further descendants )
Proto-Hellenic: *tālíkos
*teh₂-wot ?
Proto-Hellenic:
Proto-Indo-Iranian: *tāHwats
*s-ih₂ ( feminine nom.sg. ) (see there for further descendants )
Unsorted formations
Proto-Albanian: *tan- [ 4]
Proto-Armenian:
Old Armenian: *դո- ( *do- )
Proto-Balto-Slavic: *tas (see there for further descendants )
Proto-Celtic: *so (see there for further descendants )
Proto-Germanic: *sa , *þan , *þus , *þau (see there for further descendants )
Proto-Hellenic: *ho
Ancient Greek: ὁ ( ho ) , ἡ ( hē ) , τό ( tó ) , ὡς ( hōs ) , αὐτός ( autós ) , ὅδε ( hóde ) , ὁδί ( hodí ) , οὗτος ( hoûtos ) , τότε ( tóte ) - τοτέ ( toté ) , τηνίκα ( tēníka ) , τῆμος ( têmos )
Proto-Italic: *so ( as a whole pronoun ) , *sei ( locative singular )
Proto-Indo-Iranian: *sá , *sáH , *tád (see there for further descendants )
^ Dunkel, George E. (2014 ) “*só-”, in Lexikon der indogermanischen Partikeln und Pronominalstämme [Lexicon of Indo-European Particles and Pronominal Stems ] (in German), volume 2: Lexikon, Heidelberg: Universitätsverlag Winter, →ISBN , pages 732-745
^ Dunkel, George E. (2014 ) “*tó-”, in Lexikon der indogermanischen Partikeln und Pronominalstämme [Lexicon of Indo-European Particles and Pronominal Stems ] (in German), volume 2: Lexikon, Heidelberg: Universitätsverlag Winter, →ISBN , pages 779-799
^ Matasović, Ranko (2009 ) “*tal-ī-”, in Etymological Dictionary of Proto-Celtic (Leiden Indo-European Etymological Dictionary Series; 9), Leiden: Brill , →ISBN , pages 366–367
^ Demiraj, Bardhyl (1997 ) Albanische Etymologien: Untersuchungen zum albanischen Erbwortschatz [Albanian Etymologies: [ … ] ] (Leiden Studies in Indo-European; 7)[1] (in German), Amsterdam, Atlanta: Rodopi, page 179